Rheumatoid Arthritis of the Hand

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease affecting approximately 1% of the population worldwide. The hand is involved in 90% of patients, which makes it the most common site of RA manifestation.

Who. Peak onset is at 40-60 years, with a 3:1 female predominance. There is an HLA-DR4 association (70%), and smoking doubles the risk of RA and worsens its severity.

Which joints. The MCP joints are the most commonly affected and the DIP joints the least:

• MCP joints - 95%
• PIP joints - 80%
• Wrist - 60-70% early in the disease
• DIP joints - rarely affected, under 10%
• Thumb - Nalebuff deformities in 50%

Why it matters. Hand involvement causes progressive functional disability through synovitis, tendon rupture and joint destruction. Modern biologic DMARDs have revolutionised medical management, but surgery remains critical for correcting established deformities. The key is medical optimisation before surgery, then addressing the deformities in a proximal-to-distal sequence so that the deforming forces are corrected.

Synovitis comes first. RA begins with immune-mediated synovial inflammation driven by T cells, B cells and inflammatory cytokines (TNF-alpha, IL-6). The synovium hypertrophies into pannus, which invades cartilage and bone. Left unchecked, the inflammation goes on to destroy ligaments, attrit tendons and erode bone.

The sequence in the hand. The destruction runs a recognisable course:

• Early (0-2 years), synovial inflammation. Pannus forms from hypertrophic synovium and inflammatory cells, proteases degrade the articular cartilage, marginal erosions appear at the joint edges, and the collateral ligaments and volar plate stretch.
• Intermediate (2-5 years), tendon and ligament failure. Radial collateral destruction lets the extensor sublux and the fingers drift ulnarly; central slip attenuation produces the boutonniere and volar plate laxity the swan-neck; tendons rupture from attrition on roughened bone (Vaughan-Jackson, Mannerfelt).
• Late (over 5 years), fixed deformity. Bone-on-bone joint destruction, soft-tissue contractures that prevent passive correction, spontaneous ankylosis in some joints, and arthritis mutilans: severe bone resorption, the opera-glass hand.

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Ulnar drift at the MCP joints. Synovitis destroys the radial collateral ligament, the extensor tendon subluxes ulnarly, and the intrinsics then pull the fingers into ulnar deviation. The deviation is progressive and worst with grip.

The boutonniere. The central slip ruptures or attenuates and the lateral bands migrate volar to the PIP axis, so the PIP flexes. Terminal extension is preserved because the lateral bands are intact, and the DIP extends. Shortened lateral bands resist correction and the oblique retinacular ligament contracts, worsening the deformity; after 6-12 months it is fixed, no longer passively correctable, and needs arthrodesis.

The swan-neck. The primary lesion is volar plate laxity or FDS rupture: an attenuated volar plate allows the PIP to hyperextend, and FDS rupture removes the PIP flexion force. Intrinsic tightness pulls the PIP into extension, the lateral bands tighten, and the DIP flexes. Nodules in the flexor tendon can also cause it: the trigger finger causes MCP flexion, and the PIP extends in compensation.

The thumb Z-deformity. The primary lesion is CMC subluxation (Nalebuff Type III) or MCP hyperextension (Type II), and the IP flexes in compensation to allow pinch. The result is loss of opposition and pinch strength.

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2010 ACR/EULAR Classification Criteria (Diagnosis)

The 2010 ACR/EULAR criteria replaced the 1987 ACR criteria to enable earlier classification of RA, focusing on the features that predict persistent and erosive disease rather than on late deformity. A patient with synovitis in at least one joint and no better alternative diagnosis is classified as definite RA with a score of 6 or more out of 10 across four domains.

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History. Ask about the pain pattern, which in RA is worse with rest and improves with activity, and about what the hands can no longer do: grip, pinch and fine motor tasks. Then look beyond the hand:

• Systemic symptoms - fatigue, fever, weight loss
• Extra-articular disease - nodules, lung involvement, vasculitis

Examination. Look, feel and move, then test function and the tendons:

• Look - soft, boggy swelling, deformities, nodules, skin thinning
• Feel - warm, boggy MCP and PIP synovitis; ulnar head prominence
• Move - reduced range of motion, pain at end-range, crepitus
• Function - pinch and grip strength; ulnar drift with grip
• Tendons - trigger fingers, palpable ruptures

Caput ulnae syndrome. DRUJ destruction leaves the distal ulna prominent dorsally. The ulnar head is painful with forearm rotation, and it is the site of extensor tendon attrition.

Vaughan-Jackson lesion. The ulnar-sided extensors rupture in sequence as they attrit on the caput ulnae, progressing ulnar to radial:

1. EDM (extensor digiti minimi) - first to rupture
2. EDC to the ring finger - second
3. EDC to the middle finger - third

The treatment is early Darrach or hemiresection (see Surgical Technique).

Mannerfelt lesion. FPL rupture from attrition on a volar scaphoid osteophyte. It is less common than the Vaughan-Jackson lesion but causes complete loss of thumb IP flexion.

Differential Diagnosis of the Inflammatory or Deformed Hand

Serology. Rheumatoid factor is positive in 70% of patients, with a sensitivity of 70% and a specificity of 85%. Anti-CCP antibodies are also positive in 70% but are more specific, at 95%; Schellekens' 2000 validation put the figure at approximately 96-98%. Anti-CCP predicts more aggressive, erosive disease and guides earlier DMARD initiation, and patients with high titres benefit from biologic agents earlier in the disease course.

Inflammatory markers. ESR and CRP are elevated during flares and track disease activity.

Radiographs. The standard hand series is PA, lateral and oblique views. The findings follow the stage of disease:

• Early - periarticular osteopenia, soft-tissue swelling, symmetric joint space narrowing
• Late - marginal erosions at the joint edges, subluxations and deformities, bone resorption (arthritis mutilans), ankylosis

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MRI and ultrasound. Advanced imaging detects early disease (synovitis before radiographic change), assesses tendon integrity before surgery and monitors the response to DMARDs. MRI shows synovial enhancement with contrast, bone marrow oedema, tenosynovitis and early erosions.

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Algorithm

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Medical Management (Primary)

First line. Methotrexate is the gold-standard DMARD, started at diagnosis, with sulfasalazine and hydroxychloroquine as alternatives.

• 10-25mg weekly, oral or subcutaneous
• Folic acid 5mg daily alongside
• LFTs and FBC monitored every 3 months

Escalation. If the response is inadequate at 3 months, add a biologic DMARD. The target is low disease activity or remission.

• TNF-alpha inhibitors (adalimumab, etanercept)
• IL-6 inhibitors (tocilizumab)
• B-cell depletion (rituximab)
• JAK inhibitors (tofacitinib)

Symptom control. NSAIDs are for short-term pain and inflammation. Corticosteroids are used as prednisolone 5-10mg daily during flares, as an intra-articular injection for single-joint synovitis, and as bridge therapy while DMARDs take effect (6-12 weeks).

Pre-operative Optimisation

Medication. Each drug class has its own rule, and current evidence-based guidance has changed the one for methotrexate:

• Methotrexate - continue through hand surgery. It does not raise infection or wound complications and continuing it avoids a flare; the older teaching to stop it for 2 weeks is superseded
• Biologics (TNF-alpha inhibitors) - withhold one dosing cycle and schedule surgery at the trough; resume once the wound has healed and infection is excluded
• Corticosteroids - continue at the lowest effective dose, because of the risk of adrenal suppression if stopped; minimise long-term use
• NSAIDs - stop about 7 days before surgery, per local protocol

Disease activity. Schedule surgery during remission or low disease activity: active synovitis increases infection risk and impairs healing. Before elective surgery look for a low disease activity score (DAS28 under 3.2), CRP and ESR trending down, and no active synovitis at the surgical site, and defer surgery during an acute flare.

Surgical Indications

Surgery is indicated for:

• Persistent pain despite optimal medical management
• Functional impairment affecting ADLs or work
• Tendon rupture, or impending rupture (tenosynovitis)
• Progressive deformity with joint destruction
• Nerve compression (carpal tunnel syndrome is common in RA)

MCP ArthroplastyWrist Synovectomy + DarrachPIP ArthrodesisThumb Reconstruction

MCP Joint Arthroplasty with Soft Tissue Rebalancing

Consent. Warn of implant fracture or failure and recurrent ulnar drift (rates under Complications), stiffness (see Outcomes), infection at 2-3%, higher in RA, and digital nerve injury, which is rare (under 2%).

Equipment. Silicone implants of Swanson or Sutter design (sizes 0-3), MCP head and base reamers, a sagittal saw for bone resection, 3-0 and 4-0 sutures for soft-tissue repair, and 0.045" K-wires for temporary fixation.

Surgical steps

1. Approach. A dorsal longitudinal incision over the MCP joints: a single incision for index through small (4 joints), or individual incisions per digit. Elevate skin flaps to expose the extensor mechanism.
2. Extensor hood. Split the hood longitudinally, incising between the sagittal band and the extensor tendon; reflect the radial-sided hood ulnarly to expose the MCP joint capsule.
3. Synovectomy. Excise the hypertrophic synovium completely, removing pannus from the joint and tendon sheath, and send a specimen for culture to rule out infection.
4. Joint resection. Remove the metacarpal head with a sagittal saw, ream the metacarpal canal and the proximal phalanx base, and preserve the collateral ligament origins if possible.
5. Implant. Trial the size, insert the implant into the metacarpal canal first, reduce the joint, insert the distal stem into the phalanx, and confirm alignment and smooth motion.
6. Soft-tissue rebalancing (critical). Correct the ulnar drift: release the ulnar sagittal band and intrinsics, tighten (reef) the radial sagittal band, centralise the extensor tendon over the MCP, and consider radial collateral ligament reconstruction. Close the hood with 3-0 braided suture and check that the tendon centralises as the finger flexes.
7. Closure and splinting. Skin with 4-0 nylon, a bulky dressing, and a dynamic extension splint (protocol under Rehabilitation).

Soft Tissue Rebalancing is Key

The implant alone will fail without soft tissue rebalancing. The deforming forces, intrinsics pulling ulnarly and the sagittal band incompetent radially, persist after the arthroplasty. Ulnar intrinsic release with radial sagittal band tightening prevents recurrent ulnar drift; without that rebalancing, recurrent drift is quoted at 30%.

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Wrist Synovectomy and Darrach Procedure

Indications. Persistent wrist synovitis despite medical management, caput ulnae with extensor tendon attrition, and a Vaughan-Jackson lesion (EDM/EDC rupture).

Surgical steps

1. Dorsal approach. A longitudinal incision over the distal ulna and DRUJ. Identify and protect the dorsal sensory branch of the ulnar nerve, and elevate EDC and ECU to expose the DRUJ and ulnar head.
2. Synovectomy. An extensive dorsal wrist synovectomy, removing pannus from the radiocarpal joint and DRUJ and inspecting the extensor tendons for attrition.
3. Darrach (distal ulna excision). Divide the DRUJ capsule, osteotomise the distal 1.5-2cm of ulna and smooth the stump with a rongeur.
4. Tendon transfers, if ruptured. A ruptured EDM is reconstructed by transferring EIP (extensor indicis proprius) to it. Multiple ruptures (EDM with EDC ring and middle) take FDS slips as free grafts, or side-to-side transfers to an intact EDC.
5. Closure. Close the extensor retinaculum over the tendons and then the skin; splint the wrist in neutral with the forearm in neutral rotation.

Prevent Ulnar Stump Instability

After Darrach, the ulnar stump can become painful and unstable (convergence). Preserve the TFCC attachment to the stump. Consider hemiresection arthroplasty (Sauvé-Kapandji) in young, active patients to maintain DRUJ stability while decompressing the caput ulnae.

PIP Arthrodesis for Fixed Boutonniere

Indication and position. A fixed boutonniere deformity with a PIP flexion contracture over 40 degrees that is not passively correctable. The joint is fused in 30-40 degrees of flexion, the functional position for grip.

Surgical steps

1. Approach. A dorsal curved incision over the PIP joint; elevate skin flaps and split the central slip longitudinally or reflect it laterally.
2. Joint preparation. Remove all cartilage to bleeding bone, shape the bone ends into congruent surfaces and remove osteophytes, aiming for the 30-40° flexion angle.
3. Fixation. Two crossed K-wires are the most common; tension band wiring, a headless compression screw (Herbert/Acutrak) or, if bone quality is poor, a plate are the alternatives.
4. After surgery. A protective splint or buddy tape for 6 weeks, K-wire removal at 6 weeks if used, and fusion confirmed on x-ray (bridging bone across 3 of 4 cortices).

Thumb Reconstruction (Nalebuff Types)

Type I

Deformity

MCP flexion, IP extension

Surgical Treatment

MCP arthroplasty or arthrodesis + IP capsulodesis

Outcome

Good pinch restoration

Type II

Deformity

MCP hyperextension, IP flexion

Surgical Treatment

MCP arthrodesis in 15-20° flexion

Outcome

Stable pinch platform

Type III

Deformity

CMC sublux, MCP hyperext, IP flex

Surgical Treatment

CMC stabilisation (ligament reconstruction) + MCP fusion

Outcome

Complex, staged procedures

Type IV

Deformity

CMC arthritis

Surgical Treatment

CMC arthroplasty or arthrodesis

Outcome

Pain relief, maintain grip

Surgical Approach by Nalebuff Type

Type	Deformity	Surgical Treatment	Outcome
Type I	MCP flexion, IP extension	MCP arthroplasty or arthrodesis + IP capsulodesis	Good pinch restoration
Type II	MCP hyperextension, IP flexion	MCP arthrodesis in 15-20° flexion	Stable pinch platform
Type III	CMC sublux, MCP hyperext, IP flex	CMC stabilisation (ligament reconstruction) + MCP fusion	Complex, staged procedures
Type IV	CMC arthritis	CMC arthroplasty or arthrodesis	Pain relief, maintain grip

Key surgical principle. Address the primary deformity (the CMC in Type III, for example) before correcting the secondary compensatory deformities distally.

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The Rheumatoid Wrist

The proximal driver. The rheumatoid wrist drives the finger deformities from above and has its own reconstruction ladder beyond the DRUJ.

Zigzag collapse. Radiocarpal synovitis lets the carpus translate ulnarly and the wrist deviate radially, and the fingers compensate by deviating ulnarly. Volar and ulnar carpal translocation and caput ulnae accompany the collapse. Correcting the radially deviated wrist is therefore part of correcting MCP ulnar drift, which is the proximal-to-distal principle: stabilise and correct the wrist and DRUJ before MCP reconstruction.

The radiocarpal reconstruction ladder. In escalating order:

• Synovectomy and dorsal tenosynovectomy - early, to relieve synovitis and prevent extensor tendon rupture
• Partial fusion, radiolunate (Chamay) or radioscapholunate - stabilises the carpus and halts ulnar and volar translocation while preserving some midcarpal motion, in the unstable but not yet destroyed wrist
• Total wrist arthrodesis - the durable, reliable, pain-relieving salvage for the destroyed or painful wrist, especially in high-demand patients and those who load the wrist through crutches or a wheelchair. It sacrifices motion, which is acceptable when other joints or the contralateral wrist retain movement
• Total wrist arthroplasty - preserves motion for the lower-demand patient and is valuable in bilateral disease, so that both wrists are not fused, but has higher loosening and failure than arthrodesis

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Global Epidemiology

Rheumatoid arthritis affects approximately 0.5-1% of adults worldwide, with a consistent female predominance of roughly 3:1 and peak onset between 40 and 60 years. Prevalence is highest in some Indigenous North American populations and lowest in parts of sub-Saharan Africa and East Asia, reflecting genetic (HLA-DRB1 shared epitope) and environmental (notably smoking) contributions. The hand is involved in the majority of patients over the disease course, and is the most common site requiring reconstructive surgery. Critically, the incidence of major rheumatoid hand surgery has fallen substantially in the biologic era, mirroring earlier diagnosis (2010 ACR/EULAR criteria) and treat-to-target medical control (TICORA).

Side-by-Side Guideline Guidance

Registry and Outcome Evidence